Implementation of the YEARS algorithm to optimise pulmonary embolism diagnostic workup in the emergency department

Abstract

Background: Excessive use of CT pulmonary angiography (CTPA) to investigate pulmonary embolism (PE) in the emergency department (ED) contributes to adverse patient outcomes. Non-invasive D-dimer testing, in the context of a clinical algorithm, may help decrease unnecessary imaging but this has not been widely implemented in Canadian EDs.

Aim: To improve the diagnostic yield of CTPA for PE by 5% (absolute) within 12 months of implementing the YEARS algorithm.

Measures and design: Single centre study of all ED patients >18 years investigated for PE with D-dimer and/or CTPA between February 2021 and January 2022. Primary and secondary outcomes were the diagnostic yield of CTPA and frequency of CTPA ordered compared with baseline. Process measures included the percentage of D-dimer tests ordered with CTPA and CTPAs ordered with D-dimers <500 µg/L Fibrinogen Equivalent Units (FEU). The balancing measure was the number of PEs identified on CTPA within 30 days of index visit. Multidisciplinary stakeholders developed plan- do-study-act cycles based on the YEARS algorithm.

Results: Over 12 months, 2695 patients were investigated for PE, of which 942 had a CTPA. Compared with baseline, the CTPA yield increased by 2.9% (12.6% vs 15.5%, 95% CI -0.06% to 5.9%) and the proportion of patients that underwent CTPA decreased by 11.4% (46.4% vs 35%, 95% CI -14.1% to -8.8%). The percentage of CTPAs ordered with a D-dimer increased by 26.3% (30.7% vs 57%, 95% CI 22.2% 30.3%) and there were two missed PE (2/2695, 0.07%).

Impact: Implementing the YEARS criteria may safely improve the diagnostic yield of CTPAs and reduce the number of CTPAs completed without an associated increase in missed clinically significant PEs. This project provides a model for optimising the use of CTPA in the ED.

Keywords: Clinical Decision-Making; Emergency department; Venous Thromboembolism.

Figure 1

Departmental algorithm. CTPA, CT pulmonary angiography; DVT, deep vein thrombosis; PE, pulmonary embolism; PERC, Pulmonary Embolism Rule out Criteria; VTE, venous thromboembolism.

Figure 2

Run chart of CTPA yield at baseline and by PDSA cycle. Run chart depicting the CTPA yield (positive CTPAs/all CTPAs performed) in the preintervention and postintervention period. The arrow indicates when the first PDSA cycle began. The dotted line indicates the baseline median CTPA yield of 12.6% in the preintervention period. CTPA, CT pulmonary angiography; PDSA, plan-do-study-act.

Figure 3

Primary/secondary outcomes and process measures by PDSA cycle. CTPA ordered=number of CTPA/all patients investigated for PE; CTPA yield=positive CTPA/all CTPAs performed; CTPA w/DD=CTPAs with D-dimer/all CTPAs performed; and CTPA w/DD <500=CTPAs ordered with D-dimer <500/CTPAs with D-dimer. CTPA, CT pulmonary angiography; PDSA, plan-do-study-act.